The present invention relates to the field of material conveyor systems, and more particularly, to manure conveying systems and apparatus located beneath the slatted floors of livestock confinement units.
Some of the prior art inventions employ scraper blades which are moved down a manure collection alley to convey manure out from under the building, and a few of these have employed a pivoting scraper blade. Examples of these are U.S. Pat. Nos. 3,530,832; 3,240,323; 2,790,537; and 2,920,753. Other, less pertinent, prior art is disclosed in U.S. Pat. Nos. 3,693,782 (Col. 3, Lines 23-35); 2,552,743; 2,675,121; and 3,860,109. A common shortcoming of these prior structures, however, is their failure to prevent the forward movement of the blade while it is being pivoted down; with the result that the blade does not remove the first few feet of manure in the alley.
The applicant's structure eliminates this shortcoming by providing a scraper assembly which ensures that the scraper is not moved forwardly until it has been pivoted downward to its full operating position. The applicant accomplishes this result by employing a truely novel slack mechanism which permits the drive linkage to slide through guide members attached to the scraper blade within a limited range of travel. This mechanism also ensures that the scraper is not moved rearwardly until it has been fully pivoted upward to its resting position. Thus, the present invention ensures that the collection alley is fully cleared of manure after each pass, and also that the blade does not drag any manure back down the alley on its return. Another novel feature of the scraper assembly is the securement of the drive linkage at a point slightly offset from the center of the blade which causes the blade to waiver as it moves down the alley resulting in a more even distribution of the manure along the blade. The strut arrangement of the instant scraper assembly discloses further novelty by ensuring that a downward force is continually applied to the blade.
The present invention also employs a novel cable tensioning mechanism to ensure that a positive tension is continuously applied to the cable so that it is not permitted to slacken and slip at the drive unit, or become entangled. While various tensioning mechanisms have been disclosed in the prior art (particularly in U.S. Pat. Nos. 2,221,585; 3,978,737; 3,641,830; and 2,712,919), all of them employ a moveable tensioning shaft rather than a fixed shaft with a moveable tensioning sleeve as employed by the applicant. The applicant's tensioning structure is superior for large cable applications such as the present one in that the moveable sleeve can very securely hold the tensioning pulley while being moveably, but securely, mounted to a fixed base member. The instant tensioning means further includes a novel tension adjustment and indicating means which permits the user to set the cable tension in the system.